It is often useful to be able to predict the fertility of a mammalian male animal in a variety of contexts. For example, animal breeders typically go to great lengths to find male animals likely to produce offspring having desirable genetic traits. However, animal breeding is often an expensive endeavor. Males having low fertility are of reduced value due to the increased cost of breeding the animal where repeated inseminations are required to ensure impregnation. Currently, there are few reliable methods for detecting a lack of fertilizing capacity in these male animals short of statistical data compiled on their past breeding results.
Additionally, the medical community is often concerned with human fertility but has few reliable methods for evaluating the fertility of male patients. In particular, physicians have few reliable methods for detecting a lack of capacitation in the sperm of a patient.
Mammalian spermatozoa in semen cannot fertilize eggs but must undergo alterations in the plasma membrane in order to acquire fertilizing capability. The process during which the spermatozoa undergo these alterations in their membrane is termed capacitation and occurs naturally in the female reproductive tract once the sperm has been deposited.
Capacitation refers to the ability of sperm to adhere to, penetrate and fertilize susceptible ova. Penetration and fertilization not only require potentiality of the sperm to achieve a functional status, but also require that favorable conditions exist in the uterine environment. If favorable conditions exist in the mammalian uterus, sperm become capacitated and penetrate the ova. Thereafter, embryonic development begins.
To date, there have been few reliable methods for determining the fertilizing capability of the sperm of a test subject. Although it has been postulated that a variety of factors probably play a role in promoting this fertilizing capability, it is generally accepted that successful capacitation of the sperm is one of those factors. Consequently, a determination of capacitation would be a useful approach to predicting a lack of fertility in a semen specimen. Unfortunately, there are no reliable methods currently available for detecting a lack of capacitation in mammalian sperm.
It is therefore an object of the present invention to provide a method for detecting the presence of infertility in a mammalian male test subject based upon a lack of capacitation.
It is a further object of the present invention to provide a method for detecting a lack of capacitation in a sample of sperm from a mammalian male test subject.